Knockdown trestle.



Patented Mar. ll, I902. H. E. HERSH.

KNDGKDOWN TRESTLE.

(Application filed May 22, 1901.}

(No Model.)

UNITED STATES EETcE.

PATENT HARVEY E. HERSH, OF ALLENTOIVN, PENNSYLVANIA, ASSIGNOR OF ONE HALF TO JACOB ERHARDT, OF NORTHAMPTON, PENNSYLVANIA.

KNOCKDOWN TRESTLE.

rL EGEFICB-EION forming part of Letters Patent No. 695,310, dated March 1 1, 1902.

Application filed May 22, 1901. Serial No. 61, 138. (N model.)

T0 00% whom it may concern:

Be it known that I, HARVEY E. HERSH, a citizen of the United States, residing at Allentown, in the county ofLehigh and State of Pennsylvania,have invented certain new and useful Improvements in Knockdown Trestles; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the-same, reference being had to the accompanying drawings, and to figures of reference marked thereon, which form a part of this specification.

My invention relates to knockdown trestles, and has for its object to provide a trestle that is extensible and easy to take apart.

Referring to the drawings, in which like parts are similarly designated, Figure 1 is a perspective view of my trestle set up. Fig. 2 is a view of one pair of legs in knockdown position, and Fig. 3 is a side view of Fig. 2.

The cross bar or beam 5 is adjustably held within the forked ends of adjustable uprights 6, said uprights having vertical motion within the triangular frame that forms a pair of legs and comprises a rigid triangular portion having sides 7, connected by cross-pieces 8, 9, 10.

This rigid portion is capable of being lifted up or slid on sliding legs 11, and vice versa, which legs are provided with ratchet-racks 12, into which take pawls 13, secured to the portions 7 of the triangular frame. The sliding legs 11 are held to the triangular rigid portion by means of yokes L1 and 15 on the inner sides of the portions 7 and through which they can freely slide. At the apex of the triangular rigid frame the cross-piece 8 may be replaced by strap-iron binding or wooden cleats, as desired. At the apex between the side pieces 7 sufficient space is left to allow the upright 6 to be freely moved up and down, said upright being held by pawl 16, secured on the cross-pieces 8 and 9, and takes into a ratchet-rack 25 on one edge of the sliding upright 6, the lower end of which upright is guided in a suitable bracket 17, secured to one of the cross-pieces,here shown as the lower one, 10.

Hinged or other ise secured to the upright 6 is a brace or strut 18, provided at one end with a clamp-jaw 19 and a thumb-screw 20, by which said jaw can be secured intermediate the ends of the beam, which is held at or near its ends within the casting 21 on the upper end of the upright 6. Two thumbscrews 22, taking through this casting and acting upon a jam-plate 23, securely holds the beam within the casting 22 on the end of the upright 6.

The trestle that I have devised has adj ustable logs and adjustable uprights, so that it is extensible to a greater height than trestles of its kind, enables a wide supporting-base without the use of too much material, the beam is easily removed, and the entire structure is very compact when knocked down. The legs are extensible independently of one placed on slanting surfaces and still maintain its upright position.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-

A knockdown trestle, comprising a crossbeam 5, triangular rigid end frames 7, a crosspiece 8, mounted on the frames, a verticallyadjustable upright 6, having bearing in said cross-piece, castings 21 carried by said uprights adapted to receive and clamp the crossbeam thereon, a rack 25 on the outer edge of the upright, a cross-brace 9, guides mounted thereon, a pawl 16 mounted on said brace adapted to engage said rack, a cross-brace 10 mounted at the base of the rigid frame, guides 17, carried thereby, yokes 14, 15 secured to the inside of the frame near the top and base, independently-adjustable legs 11 mounted in said yokes, a rack 12 formed on the outside of said legs, a pawl 13 carried by the rigid frame to engage the rackon the legs, a brace 18, hinged to the upright and clamps 19 on the free ends thereof adapted to engage the cross-beam, for the purpose specified.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

HARVEY E. HERSH. WVitnesses:

CHARLES HORN, JAS. L. SCHAAD.

another, and the trestle can therefore be 

